Compton PD, Zamdborg L, Thomas PM, Kelleher NL.
Anal Chem. 2011 Sep 1;83(17):6868-74.
Top-down proteomics has improved over the past decade despite the significant challenges presented by the analysis of large protein ions. Here, the detection of these high mass species by electrospray-based mass spectrometry (MS) is examined from a theoretical perspective to understand the mass-dependent increases in the number of charge states, isotopic peaks, and interfering species present in typical protein mass spectra. Integrating these effects into a quantitative model captures the reduced ability to detect species over 25 kDa with the speed and sensitivity characteristic of proteomics based on
❤️ kDa peptide ions. The model quantifies the challenge that top-down proteomics faces with respect to current MS instrumentation and projects that depletion of (13)C and (15)N isotopes can improve detection at high mass by only <2-fold at 100 kDa whereas the effect is up to 5-fold at 10 kDa. Further, we find that supercharging electrosprayed proteins to the point of producing <5 charge states at high mass would improve detection by more than 20-fold.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3165072/pdf/nihms-312886.pdfDepartment of Chemistry, Northwestern University, Evanston, Illinois 60208, USA.
United States
